1. Field of the Invention
The present invention relates generally to power chucks, and, more particularly to, swivel mountings for a power chuck.
2. Description of the Related Art
Generally, power chucks are used to hold a workpiece. Typically, these power chucks are mounted on a rotatable spindle of a machine tool. Commonly, the power chuck has a body and an axially disposed actuator mounted for reciprocation therein. The power chuck also has a plurality of axially extending rocker arms with work engaging jaws spaced radially equidistantly around the actuator and mounted for rocking movement to engage and disengage the workpiece.
An improved power chuck was disclosed in U.S. Pat. No. 5,184,833 issued Feb. 9, 1993, to Kenneth Cross and Ralph J. Gonnocci. The disclosed power chuck includes a body, a plurality of work engaging jaws, a plurality of rocker arms carrying the jaws, and a plurality of swivel mountings connecting the rocker arms to the body. The swivel mountings include a tubular mounting member, a tubular bearing member disposed within the mounting member, and an annular ring member on top of the mounting member. The design of the swivel mountings, however, is subject to allowing debris to enter between the ring member and the bearing member and between the bearing member and the rocker arm during use which could lead to early wear of the various parts. An improved swivel mounting design is desired which is not subject to allowing debris to enter between its members or between its members and the rocker arm.
The design of the swivel mountings in U.S. Pat. No. 5,184,833 also requires a relatively high-profile construction, since the ring member is stacked on top of the mounting member. It is, therefore, desirable to have a swivel mounting which allows for a low-profile construction and does not have stacked members.